How to make a birchen silkie?

I have a silkie roo that I recently bought at an auction. He has the birchen coloring commonly seen on games.

I also have a birchen game/silkie mix hen that also has the birchen coloring. I was thinking of breeding them together, then breeding the chicks back to the roo. Would this work, or would the silkie be too washed out? I was also considering getting a black hen/roo to breed the offspring with.

I haven't seen any silkies with this coloring, and was just curious how hard it would be to keep the coloring. Or is there some that are already like this?

This is my hen. She does have black skin and 5 toes per foot.

Here is my roo. He does have black skin. We have clay soil here, and it had rained the day before. So his feet are caked with mud. He doesn't have the blue ears though?
Thanks for your help!!

But do you think it would work to mix my hen and roo? The only thing about her that doesn't look silkie-ish to me is the feathers, obviously, and the comb. Neither one of them have blue ears, but that could be reintroduced by another, better quality black silkie, right? Or would the mix hen wash out too much of the silkie breed, and give me a bunch of freaks?

I think that you should try and find birchen-type silkies, rather that crossing to another breed...it would be years of selective breeding to get all the silkie traits back. Although, if you're in it for the long haul...go for it!